Known equipment item management systems perform central control by bus-connecting equipment items such as air conditioners that employ a unique communication method of a manufacturer. An indoor unit includes a reception section for an optical (infrared) wireless remote controller that complies with an industry standard. In response to a user's operation, the optical wireless remote controller transmits a command of an optical signal to the indoor unit. The indoor unit receives the optical signal, exchanges information with a central management apparatus that is bus-connected via a transmission line, and centrally controlled (for example, see patent document 1). A known roof-mounted air conditioner includes a light reception section on a panel surface that can be seen by users. The air conditioner can directly receive a signal from an optical wireless remote controller (for example, see patent document 2.
[Patent Document 1] Japanese Unexamined Patent Application Publication No. 2000-111128 (FIG. 1, paragraphs 0015 and 0016)
[Patent Document 2] Japanese Unexamined Patent Application Publication No. 2003-176929, (FIGS. 1 and 4, paragraphs 0013 and 0018
In the above-described equipment item management systems, most equipment items are air conditioners that employ gas heat pumps that control compressors using engines that run on gas or the like. Especially, in Japan, the air conditioners employing gas heat pumps are used in building air conditioning systems in public facilities such as hospitals and schools, family restaurants, and offices. In these facilities, as described above, the air conditioners (equipment items) are centrally controlled by a central management apparatus of the same manufacturer using a communication method unique to the manufacturer.